AN ANNOTATED CATALOGUE OF THE BIVALVIA,POLYPLACOPHORA, SCAPHOPODA, AND CEPHALOPODA OF JEJU ISLAND, SOUTH KOREA

Abstract

This study of the Polyplacophora, Bivalvia, Scaphopoda, and Cephalopoda occurring on Jeju Island is the result of fifteen years of research into the biodiversity, biogeography, and ecology of Jeju Island mollusks. It examines the distribution, both general and local, of all species reported to date in those four classes, and also presents data on their habitat and biogeographical affinities. Specimens were collected from 56 survey stations (90 specific localities) around the island, from the intertidal and shallow subtidal zones as well as by SCUBA diving in several localities. A wide selection of relevant literature was consulted for identification purposes, as well as for taxonomic, biogeographical, and ecological information. Original descriptions, illustrations, and type localities are presented as well as relevant remarks on taxonomy, location of types, and distinguishing characteristics. Distribution maps are also provided to more clearly show the occurrence of each species around the island. A total of 272 species are treated, 19 polyplacophorans (chitons), 225 bivalves, 8 scaphopods, and 20 cephalopods. Eleven species have been added to the island's mollusk fauna: seven bivalves, three chitons, and one cephalopod, with most of those species ranging south to Southeast Asia and the Indo-Pacific. Most species of three of the four classes studied prefer warm water, with only the Polyplacophora favoring cooler water. It appears that in the above classes a slight shift toward a warmer water mollusk fauna has occurred and may be attributable to climate change. ii